South Korean researchers report that elevated levels of so-called ‘bad’ cholesterol in the blood may raise the risk of developing dementia.
The team analyzed data from 11 university hospitals across South Korea.
The dataset included 571,000 adults who did not have dementia at the start of the study.
At the start, researchers split participants into two groups based on their LDL cholesterol tests.
One group had LDL above 3.4 mmol/L; the other had LDL below 1.8 mmol/L.
Low-density lipoprotein (LDL) carries cholesterol in the blood and is commonly called ‘bad’ cholesterol.
After six months, people with low LDL were 26% less likely to be diagnosed with any form of dementia and 28% less likely to be diagnosed with Alzheimer’s disease than those with high LDL.
However, people with very low LDL had only an 18% lower chance of developing dementia compared with the high-LDL group. And those with extremely low LDL were at the same risk as people with high LDL.
Among people in the low-LDL group who regularly took statins, the risk of developing dementia was 13% lower and the risk of Alzheimer’s was 12% lower than for those who didn’t take statins.
The researchers concluded that low LDL levels are associated with a reduced risk of dementia and that statins may offer extra protection.
The study’s results were published in the Journal of Neurology, Neurosurgery and Psychiatry.
Dr. Petrula Proitsi, a genetic epidemiologist at Queen Mary’s Centre for Preventive Neurology who was not involved in the study, told BBC Science Focus that the authors did not consider several factors, including age, sex, genetic risk for dementia, and lifestyle.
